I first played surface dives at Basil deMontegue's party in Mayfair last summer. It's a game of never-ending delight and always elicits jollity.Place an open magazine (the Tatler works well) upright on the floor. Competitors then take turns to balance on one leg and pick the magazine up using only their teeth. No other limb must touch the floor or the magazine.For the more macho party members,